Pavement Preservation Update
Pavement Preservation Update
Becca Lane P.Eng. Manager, Materials Engineering and Research Office Ministry of Transportation Ontario
MTO Preservation Strategies • Extend the life of the pavement. • Applied while pavement is still in good condition. • Maintain the pavement at a high level of service. – Crack sealing – Microsurfacing – Chip Seal – Hot mix patching / single lift mill and pave – Hot in place Recycling – Cold in Place Recycling – Dowel bar retrofit, cross stitching, diamond grinding – Precast concrete pavement repair
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Crack Sealing Cost effective preservation treatment typically used to prevent water and debris from entering cracks in the pavement surface.
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Microsurfacing polymer-modified cold slurry paving system - a mixture of densegraded aggregate, asphalt emulsion, water and mineral fillers.
Microsurfacing Design Considerations • Structurally sound pavements. • Surface deficiencies (ravelling, oxidation, flushing, polishing). • Requires surface preparation to address working cracks and localized defects (aggressive sweeping/scraping). • Dry, warm weather ( > 10°C). • Seals surface • Restores surface friction • Rut filling • Addresses light to moderate flushing • Quick set - designed to open to traffic within 1 hr
Chip Seals • Description – application of asphalt and aggregate chips rolled onto the pavement
• Purpose – seal pavement surface – enrich hardened/ oxidized asphalt – improve surface friction
Fiber Modified Chip Seal Description • a chip seal application incorporating chopped fiberglass strands in the polymer modified emulsion and a covering aggregate layer.
• Purpose • Sealing the surface • Control reflective cracking
Hot In-Place Recycling • The top 35-50 mm of existing pavement is heated and scarified, rejuvenators and/or beneficiating hot mix is added, and the mix is placed.
HIR Design Considerations Suitable for pavements exhibiting distresses such as: • Ravelling and coarse aggregate loss • Slight to moderate non-working cracks • Flushing and distortions • Rutting due to poorly compacted mix • Weathered, oxidized surfaces Not suited for pavements: • Structurally deficient • Less than 70 mm thick • Requiring crossfall correction > 1.5 % • Low in air voids and recovered pen • Excessively cold patched and crack sealed
Cold In-Place Recycling • Cold in-place recycling (CIR) is a pavement rehabilitation method that recycles the existing asphalt surface, adds emulsion, and lays it back down without off-site hauling or processing. • Cold in-place recycling with Expanded Asphalt (CIREAM) uses expanded (foamed) asphalt instead of emulsion.
CIR Design Considerations • Suitable for a wide range of pavement deterioration including: – Thermal, fatigue and reflection cracking – Rutting due to mix instability – Ravelling / coarse aggregate loss – Loss of bond between layers • Requires minimum existing pavement thickness of 100 mm • Typical treatment depth 75 –125 mm • Warm, dry weather and curing period required
Diamond Grinding
Dowel Bar Retrofit
Cross-stitching
Precast concrete pavement slab repairs
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Thank you! Becca Lane, P. Eng. Manager, Materials Engineering and Research Office Ministry of Transportation Ontario Tel: 416-235-3512 Fax. 416-235-3919 email: [email protected]
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Becca Lane P.Eng. Manager, Materials Engineering and Research Office Ministry of Transportation Ontario
MTO Preservation Strategies • Extend the life of the pavement. • Applied while pavement is still in good condition. • Maintain the pavement at a high level of service. – Crack sealing – Microsurfacing – Chip Seal – Hot mix patching / single lift mill and pave – Hot in place Recycling – Cold in Place Recycling – Dowel bar retrofit, cross stitching, diamond grinding – Precast concrete pavement repair
2
Crack Sealing Cost effective preservation treatment typically used to prevent water and debris from entering cracks in the pavement surface.
3
Microsurfacing polymer-modified cold slurry paving system - a mixture of densegraded aggregate, asphalt emulsion, water and mineral fillers.
Microsurfacing Design Considerations • Structurally sound pavements. • Surface deficiencies (ravelling, oxidation, flushing, polishing). • Requires surface preparation to address working cracks and localized defects (aggressive sweeping/scraping). • Dry, warm weather ( > 10°C). • Seals surface • Restores surface friction • Rut filling • Addresses light to moderate flushing • Quick set - designed to open to traffic within 1 hr
Chip Seals • Description – application of asphalt and aggregate chips rolled onto the pavement
• Purpose – seal pavement surface – enrich hardened/ oxidized asphalt – improve surface friction
Fiber Modified Chip Seal Description • a chip seal application incorporating chopped fiberglass strands in the polymer modified emulsion and a covering aggregate layer.
• Purpose • Sealing the surface • Control reflective cracking
Hot In-Place Recycling • The top 35-50 mm of existing pavement is heated and scarified, rejuvenators and/or beneficiating hot mix is added, and the mix is placed.
HIR Design Considerations Suitable for pavements exhibiting distresses such as: • Ravelling and coarse aggregate loss • Slight to moderate non-working cracks • Flushing and distortions • Rutting due to poorly compacted mix • Weathered, oxidized surfaces Not suited for pavements: • Structurally deficient • Less than 70 mm thick • Requiring crossfall correction > 1.5 % • Low in air voids and recovered pen • Excessively cold patched and crack sealed
Cold In-Place Recycling • Cold in-place recycling (CIR) is a pavement rehabilitation method that recycles the existing asphalt surface, adds emulsion, and lays it back down without off-site hauling or processing. • Cold in-place recycling with Expanded Asphalt (CIREAM) uses expanded (foamed) asphalt instead of emulsion.
CIR Design Considerations • Suitable for a wide range of pavement deterioration including: – Thermal, fatigue and reflection cracking – Rutting due to mix instability – Ravelling / coarse aggregate loss – Loss of bond between layers • Requires minimum existing pavement thickness of 100 mm • Typical treatment depth 75 –125 mm • Warm, dry weather and curing period required
Diamond Grinding
Dowel Bar Retrofit
Cross-stitching
Precast concrete pavement slab repairs
15
Thank you! Becca Lane, P. Eng. Manager, Materials Engineering and Research Office Ministry of Transportation Ontario Tel: 416-235-3512 Fax. 416-235-3919 email: [email protected]
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